Linear electric motors are commonly provided for magnetic or air suspension vehicles, e.g. of the type described in the above mentioned patents, where they serve as propulsion means and, if necessary, as magnetic suspension and guide units for such vehicles on a track.
Generally speaking, a linear electric motor of the aforedescribed type can comprise a so-called linear stator having a core provided with a number of coils, one side of the core being provided as a pole face defining a plurality of longitudinally-spaced poles which are juxtaposed with but spaced apart from a so-called reaction rail. The magnet, although it is frequently carried by the vehicle and thus moves in the longitudinal direction, is generally referred to as a stator and the reaction rail, although stationary and mounted upon the track from which the vehicle is suspended, can frequently be referred to as an armature.
The magnetic flux generated in the magnet produces eddy currents in the reacton rail and these eddy currents react with the magnetic field in accordance with well-known linear motor principles to produce a force tending to drive the reaction rail and the magnet in opposite directions parallel to the reaction rail and hence to the longitudinal dimension of the magnet. It is this force which serves as the propulsion force.
Linear stator magnets are also provided as the suspension and guide magnets for such vehicles.
Particular attention, for the purposes of the present invention, should be directed to the linear stator magnet which is described in Bericht des Statusseminars IX, 1982 "Spurgefuhrter Fernverkehr Magnetbahnentwicklung" des Bundesministeriums fur Forschung und Technologie, Referat 2.3 (Report of the Ninth Status Seminar, 1982, "Trackbound Long Distance Magnetic Suspension Vehicle Developments" of the Federal Ministry of the Federal Republic of Germany for Research and Technology.).
Such linear stator magnets for the contactless suspension and guidance of tract vehicles, generally comprised a laminated yoke, i.e. a yoke made up from a stack of electrical sheet, defining a plurality of laminated pole shanks spaced apart from one another in the longitudinal direction, and a plurality of excitation coils respectively surrounding these shanks below the respective pole shoes whereby, to either longitudinal side of each yoke sheet stack and the shank stack, pressure plates are provided which are drawn together, e.g. by tensioning means.